1. Field of the Invention
The present invention relates to an organic electroluminescence (EL) display, and more particularly, to an adhesive type organic EL display, and a method for manufacturing the same.
2. Discussion of the Related Art
Generally, an adhesive type organic EL display comprises a lower panel having a pixel switching element and a pixel driving element formed thereon, and an upper panel having organic materials stacked thereon, in which the lower board is electrically connected with the upper board by bonding the upper and lower panels, thereby embodying the display.
A method for manufacturing a conventional adhesive type organic EL display will be described as follows.
FIG. 1 shows a cross-sectional view illustrating a conventional adhesive type organic EL display.
In FIG. 1, the display comprises a lower panel having a thin transistor formed thereon, and an upper panel having an organic EL element formed thereon.
Referring to FIG. 1, the lower panel of the organic EL display is manufactured by the following process.
First, a semiconductor layer 2 is formed using a polycrystalline silicon on a transparent substrate 1, and is removed via patterning except for a region where the thin transistor will be formed.
Next, after sequentially forming a gate insulation layer 3, and a conductive layer for a gate electrode over the entire surface of the substrate 1, the conductive layer is patterned to form a gate electrode 4.
Then, impurity ions such as phosphorus (P) are implanted to the semiconductor layer 2 using the gate electrode 4 as a mask, and then source/drain regions are formed by annealing the substrate, thereby forming an N-MOS thin transistor.
At this time, portions of the semiconductor layer 2 where the impurity ions are not implanted become channel regions.
Next, an interlayer insulation layer 5 is formed over the entire surface of the substrate comprising the above components, and the interlayer insulation layer 5 and the gate insulation layer 3 are selectively removed such that the source/drain regions of the N-MOS transistor are exposed.
Then, an electrode line 6 is formed on the substrate such that the electrode line 6 is electrically connected with the source/drain regions, respectively, thereby completing manufacture of the lower panel.
Next, referring to FIG. 1, the upper panel of the organic EL display is manufactured by the following process.
First, an anode 8 composed of a transparent conductive material having a high work function such as ITO or IZO is formed on a transparent substrate 7.
Then, an insulation layer 9 is formed on some portion of the anode 8 using an insulation material such as polyimide, and a partition wall 10 is formed on the insulation layer 9.
Next, an island-shaped spacer 11 is formed in a pixel region using another insulation material.
Then, a cathode 13 composed of a conductive material having a low work function such as aluminum is deposited on an electron implantation layer, thereby completing manufacture of the upper panel.
The upper and lower panels manufactured as described above are attached to each other.
At this time, the upper and lower panels are electrically connected by contacting the cathode 13 formed on the spacer 11 of the upper panel with the electrode line 6 of the lower panel.
However, the adhesive type organic EL display manufactured as described above has the following problems.
In general, since the spacer has a higher profile than that of the partition wall, and must be formed to have a gentle side angle, it is difficult to form the spacer.
In addition, when forming the organic material using a shadow mask, the spacer is likely to be collapsed or damaged by the shadow mask.
Furthermore, since the spacer is formed in a light emitting region, an aperture ratio is reduced.